東アフリカ・ケニヤの山地森林植生

抄録

A phytosociological survey was conducted to investigate afromontane forests mainly in Kenya. Evergreen broadleaf forest should occur as potential natural vegetation more than 1400m from sea level in Kenya. The main species were Diospyros abyssinica, Drypetes gerrardii, Vepris simplicifolia, Olea capensis subsp. hochstetteri, O. europea subsp. africana, Diospyros abyssinica, Ekerbegia capensis, Cionanthus battiscombei, and Vepris nobilis. Savanna vegetation that appeared more than 1,400m above sea level is thought to be a secondary forest of evergreen broadleaf forest. Most dry forest with Croton megalocarpus was considered as secondary vegetation. Dry forest should occur in a narrower zone than actual vegetation between the evergreen broad leaf forest and savanna as potential natural vegetation. A Prunus africana community was located at higher altitude than other broad leaf tall trees communities as potential natural vegetation. A Arundinaria alpina community and Hagenia abyssinica community were thought to be substitute vegetation of the P. africana community. A Hagenia abyssinica community is expected to appear subsequently after the Arundinaria alpina community. Juniperus procera established a natural forest on a highland cliff. Maesa lanceolata formed typical secondary shrubs. Basically Juniperus procera, Nuxia congesta, Maesa lanceolata and Clerodendrum trichotomum were considered as light demander species.